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tim laqua dot com Thoughts and Code from Tim Laqua

28Oct/070

With a blend of SD WAN and WAN optimization, you can do much to assure the performance of networks and applications.

Some years ago, Netscape implemented a network optimization technique called "reduced-wlan-path," but this is not a new idea. In fact, Netscape worked with the IEEE (Internet Engineering Task Force) in the early 1990s to design network optimizations techniques for IEEE 802.11 (mobile) wireless networks, and there are resources where you can find information about WAN and SD WAN at https://www.fortinet.com/resources/cyberglossary/sd-wan-explained.

This process was documented in two research papers. The first paper was "Reduced WLAN Path: IEEE 802.11 Network for Mobile Broadband" published in 2000 by Martin Sousa at the University of Washington, Seattle and Steven Schultz at NASA Ames Research Center in Moffett Field, California. The second paper was "Efficient Network Discovery with Reduced WLAN Path: IEEE 802.11 Network for Mobile Broadband" published in 2004 by Michael J. Breuer at the University of Pennsylvania and colleagues. Both of these papers describe the use of reduced-wlan-path on IEEE 802.11 and lower-level network management techniques for improved performance and reduction of contention (a higher bandwidth connection on the network).

Overview

Reduced-wlan-path works with a unique mechanism to enhance path optimization within the protocol stack. In short, if there is contention between mobile IEEE 802.11 WLANs and WAN networks, reduced-wlan-path lets IEEE 802.11 MOH (multihoming) work between the mobile and WAN, by letting one WLAN and one WAN manage their own path selection and other connections between the two.

One result of this improvement to the 802.11 protocol stack is that the maximum data rate between IEEE 802.11 MOH enabled networks (500 Mbps) is improved dramatically.

In addition, for clients, applications and WANs that have both WAN and Mobile networks configured (or a combination of both), it is possible to make sure that data flows are not disturbed by nodes on the WAN while still providing the potential to make calls when some applications (such as file servers) use the low latency of the Mobile network. In fact, this type of mitigation can provide the services that the IEEE 802.11 MOH provides.

Reduced-Wlan-Path is a form of low-level packet manipulation and optimization designed to provide an easy solution for network optimization and to provide maximum performance for WANs and MOH enabled networks. The important thing to note about Reduced-Wlan-Path is that it involves manipulating IEEE 802.11 traffic and ultimately it does not provide traffic filtering. When you choose Reduced-Wlan-Path and other strategies, the ultimate purpose of the resulting traffic is still that of providing connectivity for WAN and Mobile devices.

Tutorial

How can I get reduced-wlan-path turned on for my Cisco Nexus 2100 Switch?

Configure your new router as an IEEE 802.11 Mobile IEEE 802.11 Gateway/AP. Enable the reduced-wlan-path (RT-XLEW) feature in the mobile interfaces. Configure the reduced-wlan-path feature as follows:

Command Interface Interface Ports Link Speed MAC Address MWE

(Lower, Lower, Lower) Wireless In WAN-AD Interfaces DSCP/IPv4 Range (To/From Lower Level) MWE